Zoned for both office and light industrial use, the mass timber 1 De Haro is a first both in San Francisco and California as a whole. Wood is literally on the rise with the tallest mass timber building on the West Coast, at 19 stories, being built in Oakland, California.When complete, 1510 Webster Street will be the tallest, mass-timber building in California. California building codes were updated in July to allow for the construction of mass timber buildings up to 18 stories tall. California recently update its building code to allow mass timber buildings of up to 18 stories in height. Brookfield and Hacker Architects have unveiled a 300000squarefoot mass timber office building slated to break ground on Pier 70. Built in 1943 to house U.S. Navy blimps, Hangar B is the largest clearspan wooden structure in the world.